1. Field of Invention
The invention relates to the methods for preparing a perovskite thin film and a solar cell and, in particular, to the method for preparing the solar cell using the perovskite film as the active layer.
2. Related Art
Recently, with the issue of increasing energy consumption, rising oil price and global warming induced by fossil energy, searching an alternative energy without sequela becomes an important subject. The alternative energy under the spotlight nowadays encompasses hydraulic power, wind power, solar power, geothermal energy, etc. Among them, the solar cell (which converts solar energy to electricity) is one of the most attractive sources since it has several advantages such as low pollution, less environmental limitation and high safety.
Perovskite solar cell uses a perovskite film as the active layer (also called light-absorbing layer). Perovskite material has a strong absorption on the visible light and has a wide absorption range, therefore small amount of the material can produce high short-circuit current when it was applied in the solar cell. Perovskite solar cell also has a high open-circuit voltage, therefore has high power conversion efficiency (PCE).
The conventional method for preparing a high efficiency perovskite solar cell, the perovskite active layer is fabricated by an evaporation technique. However, an expensive evaporator and a high vacuum environment are required for the evaporation method and the procedure for making vacuum not only takes a lot of time and cost but also the property of the perovskite thin film is difficult to be accurately controlled.
Therefore, it is an important subject to provide a method for preparing the perovskite film and therefore the solar cell where the perovskite active layer is formed without using the evaporation technique and the property of the perovskite film can be accurately controlled and reproducible.